[deliverable/linux.git] / drivers / video / backlight / jornada720_bl.c

/*
 *
 * Backlight driver for HP Jornada 700 series (710/720/728)
 * Copyright (C) 2006-2009 Kristoffer Ericson <kristoffer.ericson@gmail.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 or any later version as published by the Free Software Foundation.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/backlight.h>
#include <linux/device.h>
#include <linux/fb.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>

#include <mach/jornada720.h>
#include <mach/hardware.h>

#include <video/s1d13xxxfb.h>

#define BL_MAX_BRIGHT	255
#define BL_DEF_BRIGHT	25

static int jornada_bl_get_brightness(struct backlight_device *bd)
{
	int ret;

	/* check if backlight is on */
	if (!(PPSR & PPC_LDD1))
		return 0;

	jornada_ssp_start();

	/* cmd should return txdummy */
	ret = jornada_ssp_byte(GETBRIGHTNESS);

	if (jornada_ssp_byte(GETBRIGHTNESS) != TXDUMMY) {
		pr_err("get brightness timeout\n");
		jornada_ssp_end();
		return -ETIMEDOUT;
	} else /* exchange txdummy for value */
		ret = jornada_ssp_byte(TXDUMMY);

	jornada_ssp_end();

	return (BL_MAX_BRIGHT - ret);
}

static int jornada_bl_update_status(struct backlight_device *bd)
{
	int ret = 0;

	jornada_ssp_start();

	/* If backlight is off then really turn it off */
	if ((bd->props.power != FB_BLANK_UNBLANK) || (bd->props.fb_blank != FB_BLANK_UNBLANK)) {
		ret = jornada_ssp_byte(BRIGHTNESSOFF);
		if (ret != TXDUMMY) {
			pr_info("brightness off timeout\n");
			/* turn off backlight */
			PPSR &= ~PPC_LDD1;
			PPDR |= PPC_LDD1;
			ret = -ETIMEDOUT;
		}
	} else  /* turn on backlight */
		PPSR |= PPC_LDD1;

		/* send command to our mcu */
		if (jornada_ssp_byte(SETBRIGHTNESS) != TXDUMMY) {
			pr_info("failed to set brightness\n");
			ret = -ETIMEDOUT;
			goto out;
		}

		/* at this point we expect that the mcu has accepted
		   our command and is waiting for our new value
		   please note that maximum brightness is 255,
		   but due to physical layout it is equal to 0, so we simply
		   invert the value (MAX VALUE - NEW VALUE). */
		if (jornada_ssp_byte(BL_MAX_BRIGHT - bd->props.brightness) != TXDUMMY) {
			pr_err("set brightness failed\n");
			ret = -ETIMEDOUT;
		}

		/* If infact we get an TXDUMMY as output we are happy and dont
		   make any further comments about it */
out:
	jornada_ssp_end();

	return ret;
}

static const struct backlight_ops jornada_bl_ops = {
	.get_brightness = jornada_bl_get_brightness,
	.update_status = jornada_bl_update_status,
	.options = BL_CORE_SUSPENDRESUME,
};

static int jornada_bl_probe(struct platform_device *pdev)
{
	struct backlight_properties props;
	int ret;
	struct backlight_device *bd;

	memset(&props, 0, sizeof(struct backlight_properties));
	props.type = BACKLIGHT_RAW;
	props.max_brightness = BL_MAX_BRIGHT;
	bd = backlight_device_register(S1D_DEVICENAME, &pdev->dev, NULL,
				       &jornada_bl_ops, &props);

	if (IS_ERR(bd)) {
		ret = PTR_ERR(bd);
		pr_err("failed to register device, err=%x\n", ret);
		return ret;
	}

	bd->props.power = FB_BLANK_UNBLANK;
	bd->props.brightness = BL_DEF_BRIGHT;
	/* note. make sure max brightness is set otherwise
	   you will get seemingly non-related errors when
	   trying to change brightness */
	jornada_bl_update_status(bd);

	platform_set_drvdata(pdev, bd);
	pr_info("HP Jornada 700 series backlight driver\n");

	return 0;
}

static int jornada_bl_remove(struct platform_device *pdev)
{
	struct backlight_device *bd = platform_get_drvdata(pdev);

	backlight_device_unregister(bd);

	return 0;
}

static struct platform_driver jornada_bl_driver = {
	.probe		= jornada_bl_probe,
	.remove		= jornada_bl_remove,
	.driver	= {
		.name	= "jornada_bl",
	},
};

module_platform_driver(jornada_bl_driver);

MODULE_AUTHOR("Kristoffer Ericson <kristoffer.ericson>");
MODULE_DESCRIPTION("HP Jornada 710/720/728 Backlight driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
13a7b5dc KE	1	/*
	2	*
	3	* Backlight driver for HP Jornada 700 series (710/720/728)
	4	* Copyright (C) 2006-2009 Kristoffer Ericson <kristoffer.ericson@gmail.com>
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License version
	8	* 2 or any later version as published by the Free Software Foundation.
	9	*
	10	*/
	11
20c225cb JH	12	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20c225cb JH	13
13a7b5dc KE	14	#include <linux/backlight.h>
	15	#include <linux/device.h>
	16	#include <linux/fb.h>
	17	#include <linux/kernel.h>
	18	#include <linux/module.h>
	19	#include <linux/platform_device.h>
	20
	21	#include <mach/jornada720.h>
	22	#include <mach/hardware.h>
	23
	24	#include <video/s1d13xxxfb.h>
	25
	26	#define BL_MAX_BRIGHT 255
	27	#define BL_DEF_BRIGHT 25
	28
	29	static int jornada_bl_get_brightness(struct backlight_device *bd)
	30	{
	31	int ret;
	32
	33	/* check if backlight is on */
	34	if (!(PPSR & PPC_LDD1))
	35	return 0;
	36
	37	jornada_ssp_start();
	38
	39	/* cmd should return txdummy */
	40	ret = jornada_ssp_byte(GETBRIGHTNESS);
	41
	42	if (jornada_ssp_byte(GETBRIGHTNESS) != TXDUMMY) {
20c225cb	43	pr_err("get brightness timeout\n");
13a7b5dc KE	44	jornada_ssp_end();
	45	return -ETIMEDOUT;
	46	} else /* exchange txdummy for value */
	47	ret = jornada_ssp_byte(TXDUMMY);
	48
	49	jornada_ssp_end();
	50
	51	return (BL_MAX_BRIGHT - ret);
	52	}
	53
	54	static int jornada_bl_update_status(struct backlight_device *bd)
	55	{
	56	int ret = 0;
	57
	58	jornada_ssp_start();
	59
	60	/* If backlight is off then really turn it off */
	61	if ((bd->props.power != FB_BLANK_UNBLANK) \|\| (bd->props.fb_blank != FB_BLANK_UNBLANK)) {
	62	ret = jornada_ssp_byte(BRIGHTNESSOFF);
	63	if (ret != TXDUMMY) {
20c225cb	64	pr_info("brightness off timeout\n");
13a7b5dc KE	65	/* turn off backlight */
	66	PPSR &= ~PPC_LDD1;
	67	PPDR \|= PPC_LDD1;
	68	ret = -ETIMEDOUT;
	69	}
	70	} else /* turn on backlight */
	71	PPSR \|= PPC_LDD1;
	72
	73	/* send command to our mcu */
	74	if (jornada_ssp_byte(SETBRIGHTNESS) != TXDUMMY) {
20c225cb	75	pr_info("failed to set brightness\n");
13a7b5dc	76	ret = -ETIMEDOUT;
b317c833	77	goto out;
13a7b5dc KE	78	}
	79
	80	/* at this point we expect that the mcu has accepted
	81	our command and is waiting for our new value
	82	please note that maximum brightness is 255,
	83	but due to physical layout it is equal to 0, so we simply
	84	invert the value (MAX VALUE - NEW VALUE). */
	85	if (jornada_ssp_byte(BL_MAX_BRIGHT - bd->props.brightness) != TXDUMMY) {
20c225cb	86	pr_err("set brightness failed\n");
13a7b5dc KE	87	ret = -ETIMEDOUT;
	88	}
	89
	90	/* If infact we get an TXDUMMY as output we are happy and dont
	91	make any further comments about it */
	92	out:
	93	jornada_ssp_end();
	94
	95	return ret;
	96	}
	97
9905a43b	98	static const struct backlight_ops jornada_bl_ops = {
13a7b5dc KE	99	.get_brightness = jornada_bl_get_brightness,
	100	.update_status = jornada_bl_update_status,
	101	.options = BL_CORE_SUSPENDRESUME,
	102	};
	103
	104	static int jornada_bl_probe(struct platform_device *pdev)
	105	{
a19a6ee6	106	struct backlight_properties props;
13a7b5dc KE	107	int ret;
	108	struct backlight_device *bd;
	109
a19a6ee6	110	memset(&props, 0, sizeof(struct backlight_properties));
bb7ca747	111	props.type = BACKLIGHT_RAW;
a19a6ee6 MG	112	props.max_brightness = BL_MAX_BRIGHT;
	113	bd = backlight_device_register(S1D_DEVICENAME, &pdev->dev, NULL,
	114	&jornada_bl_ops, &props);
13a7b5dc KE	115
	116	if (IS_ERR(bd)) {
	117	ret = PTR_ERR(bd);
20c225cb	118	pr_err("failed to register device, err=%x\n", ret);
13a7b5dc KE	119	return ret;
	120	}
	121
	122	bd->props.power = FB_BLANK_UNBLANK;
	123	bd->props.brightness = BL_DEF_BRIGHT;
	124	/* note. make sure max brightness is set otherwise
	125	you will get seemingly non-related errors when
	126	trying to change brightness */
13a7b5dc KE	127	jornada_bl_update_status(bd);
	128
	129	platform_set_drvdata(pdev, bd);
20c225cb	130	pr_info("HP Jornada 700 series backlight driver\n");
13a7b5dc KE	131
	132	return 0;
	133	}
	134
	135	static int jornada_bl_remove(struct platform_device *pdev)
	136	{
	137	struct backlight_device *bd = platform_get_drvdata(pdev);
	138
	139	backlight_device_unregister(bd);
	140
	141	return 0;
	142	}
	143
	144	static struct platform_driver jornada_bl_driver = {
	145	.probe = jornada_bl_probe,
	146	.remove = jornada_bl_remove,
	147	.driver = {
	148	.name = "jornada_bl",
	149	},
	150	};
	151
81178e02	152	module_platform_driver(jornada_bl_driver);
13a7b5dc KE	153
	154	MODULE_AUTHOR("Kristoffer Ericson <kristoffer.ericson>");
	155	MODULE_DESCRIPTION("HP Jornada 710/720/728 Backlight driver");
	156	MODULE_LICENSE("GPL");